Many don’t care about affairs but unless one has been a victim of a spouse cheating, affairs take on a different meaning. It feels like somebody is putting a knife through you, and wreaking havoc on the family, esp. when children are involved.
Bill Clinton treated Hillary badly - we can all agree on that - but after the first few times she had choices to make. She made the worse choice possible - she assisted with keeping his abused powerless victims silent.
That's an immoral choice on Hillary's part. An unforgivable choice... worse by far then being unfaithful.